Ln3+-Catalyzed Alcoholysis of Organophosphates: New Methodology for the Catalytic Transformation of Phosphorus Pesticides and CW Agents

摘要

The title project involved investigation of the metal ion catalyzed alcoholysis (e.g. methanolysis) of neutral organophophorus (OP)ester compounds. These included several members of the phosphate (ArO)(RO)(2P=O) and phosphorothioate (ArS)(RO)(2P=O) classes, as well as phosphonate (ArO)CH3(OR)(P=O) and phosphonothioate (ArS)CH3(RO)(P=O) classes. Some work was conducted on the P=S phosphorothionate esters which are common pesticides. In general it was found that La3+ ion, in the presence of one equivalent of alkoxide, provided an efficient catalyst capable of decomposing all P=O classes of the above neutral OP agents (except P=S derivatives) at rates between 7 to 9 orders of magnitude larger than the background reactions at the same pH. The Zn(II) and Cu(II) complexes of 1,5,9-triazacyclododecane, as their monoalkoxy forms, are also powerful catalysts for decomposing these OP materials, including the P=S examples. Considerable study was devoted to determining the mechanism of the reactions which is suggested to involve a dual role for the catalyst as both a Lewis acid and deliverer of a metal bound alkoxide to the OP substrate. The metal catalyzed alcoholysis procedures are simple, proceed rapidly at room temperature and essentially neutral pH conditions, give essentially non-toxic ester products from decomposition of the OP simulants investigated.